| Summary: | 博士 === 國立中央大學 === 化學研究所 === 97 === In this thesis, our work mainly focuses on the synthesis of metal compounds with novel structures by a hydrothermal method. Compared with a large number of publications of transition-metal compounds, the research on the synthesis of novel uranium or lanthanide compounds is considerable less. At the same time, the past studies also show that uranium- and(or) lanthanide-bearing materials display many interesting structural chemistry and potential applications, therefore, we aim at synthesizing new metal compounds with various architectures by adjusting the ratio of reactant in a hydrothermal method and then characterize their properties, such as luminescence and catalytic properties. 34 compounds in this research are divided into two series based on metal centers.
The first series is to synthesize and characterize novel uranium-containing compounds by choosing appropriately organic templates or(and) ligands into fluoride or phosphate systems. U-1 is an organically templated mixed-valent uranium(IV)/uranium(VI) oxyfluoride with a hybrid network structure (1D + 2D). U-2 is the first example of a mixed-metal uranium oxyfluoride incorporating an organic ligand. Bimetallic compounds are highly interesting because the second metal provides the possibility of incorporating organic ligands into the extended structures. U-3 is a new uranium(IV) fluorooxalate, in which oxalate ligands show bisbidentate coordination to the U atoms acting as pillars between adjacent uranium fluoride layers to produce an extended 3D network. U-4 and U-5 are the first examples of organically templated uranium fluorooxalates. Both of them consist of anionic [U2F6(C2O4)3]4- layers separated by organic ammonium cations and lattice water molecules. The building units within the layers are connected in different ways, which are very likely directed by the organic templates. U-6 and U-7 are two mixed-metal uranium compounds with a pillared layer structure. The organic ligands coordinate to the Cu atoms within adjacent uranium/copper phosphate( or arsenate) layers to generate a pillared layer structure. The other uranium compounds are categorized in appendix A.
The second series focuses on synthesis, characterization, and properties of novel lanthanide phosphates or phosphates. The 12 compounds (Ln-1-Ln-12) are isostructural and feature a 3D architecture in which 2D layers of [Ln(H2O)(HPO3)]+ are pillared by oxalate ligands. The structures of four isostructural organically templated lanthanide oxalatophosphates (Ln-13-Ln-16) contain 2D layers of lanthanide oxalates which are linked by dihydrogen phosphate units and bismonodentate oxalate ligands to form 3D frameworks. The three isostructural lanthanide phosphates (Ln-17-Ln-19) are observed for the first time by using a multidentate organic ligand, which was never used in metal phosphate and(or) phosphite systems before. Some of those lanthanide-bearing materials display red, blue, green, and near-IR luminescence. At the same time, it is also proved that the Yb and Gd compounds are effective catalysts for the Biginelli reaction.
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